alluvial

[19] Alluvial material is material that has been washed down and deposited by running water. Hence the term; for its ultimate source, Latin lavere (a variant of lavāre, which produced English latrine, laundry, lava, lavatory, lavish, and lotion), meant ‘wash’. Addition of the prefix ad- ‘to’ changed lavere to luere, giving alluere ‘wash against’. Derived from this were the noun alluviō (source of the English technical term alluvion ‘alluvium’) and the adjective alluvius, whose neuter form alluvium became a noun meaning ‘material deposited by running water’. English adopted alluvium in the 17th century, and created the adjective alluvial from it in the 19th century. If Latin alluere meant ‘wash against’, abluere meant ‘wash away’. Its noun form was ablūtiō, which English acquired as ablution in the 14th century. => ABLUTION, LATRINE, LAUNDRY, LAVATORY, LAVISH, LOTION